REPRESENTATIVE IMAGE: Online hostess Sun Xiaohou, who is dressed as a man, sings during a live broadcast in Beijing, April 2, 2015.

Reuters/Jason Lee/Files

BEIJINGChina is tightening control of online music, paying particular attention to content and jacking up already tight censorship of the Internet.

From Jan. 1, companies offering online music should police content before making it available, the Ministry of Culture said on its website. China’s three biggest Internet companies, Alibaba Group Holding Ltd, Tencent Holdings Ltd and Baidu Inc all have music streaming platforms.

This edict is the latest strike in a multi-year campaign to “cleanse” both the Internet and culture more broadly of material the ruling Communist Party might deem a threat to China’s stability. The country already operates what experts say is one of the world’s most sophisticated online censorship mechanisms.

Baidu declined to comment. Alibaba and Tencent were not available for immediate comment.

The self-censorship system for music mirrors those currently in place at Internet companies, which employ large teams to scour the firms’ websites and apps and eradicate sensitive material.

Academics and censorship experts say the self-policing, with punitive measures for failure to remove “harmful” content, encourages companies and individuals to be conservative and censor more than may be necessary, in order to avoid punishment.

Despite the crackdown, music industry professionals say that China is becoming an increasingly important market, especially as music streaming gains popularity and a growing middle-class pays for high-quality services.

The government has been trying to shake off the country’s image as a market notorious for rampant music and entertainment piracy, issuing new regulations and punishments for offenders.

The ministry also asked online music platforms to submit information about their music to government officials from April 1.

In August, the ministry banned a list of 120 songs from being distributed online because they were “morally harmful”.

A large chunk of the songs were made by a handful of hip-hop artists, mirroring Western countries’ moral panic over rap in the 1990s and early 2000s.